The ePower Tiger 550: Hot & Quiet

The distinctive black heatsinks are very similar to those in the ePower
Lion, and there is little doubt that the OEM is the same: Topower.
Topower manufacturers power supplies for several well known brands, including
OCZ and Tagan. In the past, we have found that their products are often quiet,
but also undercooled.

The heatsinks in the Tiger are smaller and thinner than the Topower-based models
we've seen in the past, but this is not necessarily a bad thing, as the heatsinks
were often so large that they left little room for airflow. There is more open
space in the Tiger, but the internal components are still very tightly packed.

The black heatsinks cover a lot of area but are smaller than other models
from the same OEM.

The heatsinks are situated directly beneath the fan and do not allow much airflow
to pass through them; only about a quarter of the heatsink area is open enough
to allow air through. Luckily, the fins themselves are only about half a centimeter
thick, so the air doesn't have to go very far to flow through.

The heatsinks are slitted to allow air to flow through them. About 75% of
the area is restricted.

The fins are thin enough to allow air to pass through them.

FAN

Sleeve bearing fans are quiet, but aren't designed for high heat environments
like a power supply.

The fan is a low speed, sleeve bearing model from Globe Fan. All of these are
good signs for noise. However, sleeve bearings are not well suited to high-heat
applications, and generally have a shorter lifespan than ball bearing fans.

All of the cable sets are detachable, including the main ATX and AUX plugs.
As mentioned, they are color coded, with a blue plug for the end that plugs
into the power supply and black plugs for the peripherals. In addition, all
of the cables except for the fan headers are sleeved. Most cables use black
plastic mesh, but the two PCIe cables are sleeved in some kind of metal mesh
to reduce EMI. These two cables also come with ferrite rings as a further measure
against EMI. These measures are intended to reduce ripple voltage, but such
gimmicks are usually unnecessary for the majority of users.

Of more interest are the two fan headers, which supply a variable voltage depending
on the internal temperature of the power supply. The voltage is the same as
received by the internal cooling fan, so our testing will characterize the behavior
of these headers as well. Fans with 3-pin and 4-pin Molex headers are both compatible,
as both headers are included on the cables.